The size doesn't have to match, Hoosier: you just have to have enough room to store what you've got, or plan to get.

Sound good?

I've created 2 paritions on my external 2.5" drive. The first, 'Backup' is roughly 5gb (12%) less than the size of my internal drive. It's not a good idea to completly full a drive (those of you who have lost a drive will probably remember it happened just as you filled what little available space you had on your drive). The second partition obvously consumes the rest.